Ladder holder



Aug. 30, 1966 J. F. MACHEN 3,269,436

LADDER HOLDER Filed July 27, 1964 2 Sheets--Sheet 1 IN V EN TOR:

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J. F. MACHEN LADDER HOLDER Aug. 30, 1966 2 Sheets-Sheet 2 Filed July 27. 1964 IN VEN TOR:

United States Patent 3,259,436 LADDER HOLDER James F. Machen, 2495 Rohinwood Ave, Toledo, Ohio Filed July 27, 1964, Ser. No. 385,321 1 Claim. (Cl. 182170) This invention relates to self-supporting ladders and more specifically to an improved self-supporting attachment for rung or extension ladders.

In many situations where it is necessary to obtain overhead access yet where a ladder cannot be leaned, it is often desirable to employ a rung or extension ladder made self-supporting my means of an accessory as set forth in my copending application for a Ladder Holder, Serial No. 308,706, filed September 13, 1964, now Patent No. 3,165,169. That application discloses an adjustable two-legged attachment which clamps to a ladder rung and makes it self-supporting when the legs are arranged in a tripod configuration with the ladder. Such a device offers advantages over scaffolding or other self-supporting equipment when reaching overhead 20 to 30 ft. because it is typically less cumbersome, faster to erect, and much less expensive.

Experience with ladder supports of this type has shown, however, that for the improved comfort of the climber a means to minimize ladder twisting would be highly desirable. Many light weight rung ladders are quite flexible in twisting, and unless the ladder is leaned or held in such a way that twisting is prevented at the point of support, the climber may feel somewhat uneasy when high on the ladder.

For ease of storage, it has also been found desirable to provide a means whereby the self-supporting accessory will fold against the ladder and may be stored without detachment. Without such a feature, it is necessary to detach the accessory and store it separately after each usage.

Accordingly, in addition to other objects and advantages of such self-supporting accessories for rung or extension ladders, it is an object of the present invention to provide an improved accessory wherein ladder twisting, wiggle, or sway is minimized or eliminated.

Another object of this invention is to provide a selfsupporting accessory that will fold against the ladder for storage without detachment.

Another object of this invention is to provide a selfsupporting accessory that will incorporate extra safety features in its basic construction and additionally enhence the safe use of the ladder.

Other objects and further advantages of this invention will become more apparent when the following description is taken in conjunction with the drawings, in which:

FIG. 1 is a perspective elevation view of an extension ladder supported by a preferred embodiment of this invention.

FIG. 2 is an enlarged fragmentary elevation view of the back of the ladder in the vicinity of the rung connection, showing the details thereof.

FIG. 3 is a cross-sectional view taken along line 33 in FIG. 2.

FIG. 4 is an enlarged view of the rung fitting (image plane of view parallel to plane of ladder).

FIG. 5 is a bottom view of the rung fitting, related to the view of FIG. 4.

Referring to FIG. 1, an extension ladder, consisting of lower section and upper section 11, is supported by means of legs 12 and 12' through a common connecting fitting 13 which is removably attached to top rung 14 of lower ladder section 10. J-hooks 15 extend down from fitting 13 and under next lower rung 16 to distribute 3,269,436 Fatented August 30, 1966 the load at the connection over two rungs (for safety purposse), and also to act as a moment arm against eccentric loading about rung 14.

Legs 12 and 12 are of fixed length, sized to suit, and form tripod configuration with the lower ladder section 10 when in use supporting the ladder. Safety chain 17 extends around bottom rung 18, out to snap-fastener 19 (hidden), on leg 12, across to snap-fastener 19' on legs 12, and back to bottom rung 18. Snap-fastener 20 on one end of chain 17 permits the chain length to be adjusted so that it may accommodate various leg positions and set-ups with the ladder. Chain 17 serves to prevent legs 12 and 12 from accidentally shifting position. Legs 12 and 12' are also equipped with rubber feet 21.

Referring to FIGS. 2, 3, 4, and 5, rung fitting 13 is secured to rung 14 by means of L-bolt 22 tightened by Wing-nut 23. Fitting 13 has a channel shape in crosssection for easy attachment to and removal from rungs of various sizes and shapes. J-hooks 15 are 'angularly disposed in fitting 13 and are anchored by means of jam nuts 24.

Lugs 25 and 25' have integral gear sectors 26 and 26, and pivot pins 27 and 27 (respectively throughout). Pins 27 and 27' are pivoted into rung fitting 13 on parallel centerlines, which are also parallel to the longitudinal axis of the ladder, and which are spaced such that gear sectors 26 and 26' are in mesh.

Clevis fittings 28 and 28 learned at the tops of legs 12 and 12' provide hinged leg connections to lugs 25 and 25' by means of hinge pins 29 and 29 which fit through mating holes 30 and 30'. The centerlines of hinge pins 29 and 29, as determined by holes 30 and 3t), lie in a plane perpendicular to the longitudinal axis of the ladder.

Spring pins 31 engage annular grooves 32 and 32' of pivot pins 27 and 27 to retain lugs 25 and 25' in rung fitting 13. Cotter pins 33 retain hinge pins 29 and 29.

The hinged motion of leg 12 about hinge pins 29 is free and independent of the hinged motion of leg 12' about hinge pin 29'. However, because of the meshing of gear sectors 26 and 26', the pivoted rotation of leg 12 about pivot pin 27 is in strict geared coordination with that of leg 12' about pivot pin 27'. If the ladder is held fixed, legs 12 and 12 are thus free only to swing together or apart in opposite directions about pivot pins 27 and 27'. Both legs cannot swing in the same direction simultaneously around the ladder axis. Conversely, if the legs are held fixed, the ladder is held against rotation.

Thus the mechanism described fulfills the desired function of holding the ladder so as to resist twisting, accomplishing a major object of this invention.

In order to provide that the legs may fold against the ladder for storage without detachment, holes 30 and 30' for hinge pins 29 and 29 may simply be offset from pivot pins 27 and 27' by a spacing sufficient that no interference with rung 16 results when the legs are folded together and fiat. J-hooks 15 act as a moment arm against eccentric loading about rung 14 resulting from this offset, as was explained earlier.

The preferred embodiment of this invention shown and described employs legs of fixed length. For adjustability of height, upper ladder section 11 may simply be raised or lowered to suit. In loading upper section 11 above rung 14, care must be taken to insure that the load does not overhang beyond the boundaries of the base (roughly the triangle described by chain 17), otherwise tipping will result.

Also, to insure that the ladder is not overstressecl, the maximum cantilevered extension of upper section 11 beyond rung fitting 13 should not exceed one-fourth of the fully extended length of the ladder. Stresses in the ladder side rails when loaded at this cantilevered extension will approximate the normal maximum stresses at full extension with the same load with the ladder leaned as in normal usage. When upper section 11 is limited to this maximum permissible extension, tipping due to overhung loads also is virtually impossible.

A rung fitting that provides geared leg coordination, such as disclosed in this application, may also be applied to an adjustable two-legged attachment such as described in my co-pending application, previously mentioned. When applied thereto, it would oifer the same primary advantage of minimizing ladder twisting and would merely require the substitution of the geared rung connecting fitting of this invention or its functional equivalent.

Other variations of the principles disclosed may be applied in other embodiments of this invention. For example, it is not an absolute requirement that pivot pins 27 and 27' 'be parallel to the longitudinal axis of the ladder. Neither is it entirely essential that hinge pins 29 and 29 be in a plane perpendicular to the ladder axis. Other orientations of the hinges and pins are possible, as are other geared interconnections, such as bevel gears. The fitting 13 may be attached to rungs other than rungs 14 and 16. Also, chain 17 is not absolutely necessary, for instance where spikes are employed at the lower ends of legs 12 and 12' instead of rubber feet 21.

Those skilled in the art will understand that such variations, and many other embodiments employing identical or basically similar principles may be devised. It should therefore be understood that this invention is not limited to the specific construction shown and described except as so provided in the appended claim.

I claim: A ladder supporting device comprising: a fitting engageable in fixed alignment with said ladder; fastening means for said fitting also engageable with said ladder; two legs; two terminals fastened to said fitting; offset portions on said terminals; gear teeth on said offset portions; said terminals rotatable about fixed axes with respect to said fitting; a geared interconnection between said terminals through said gear teeth; hinges connecting said legs respectively and independently with said terminals.

References Cited by the Examiner UNITED STATES PATENTS 12/1892 Burgess 1s2 9/1910 Samuelson 182-170 

